Ticket #5: Implement findPokemonById Assigned to: Groups 8 & 9
Estimated time: 25 minutes
Difficulty: ⭐⭐⭐ Medium-Hard

What You're Doing Create a new function findPokemonById that finds a Pokemon by its ID number. This ticket focuses on error handling and robust function design.

Tasks

1. ✍️ Write comprehensive tests FIRST (TDD)
2. 💻 Implement the function with proper error handling
3. 🚨 Handle edge cases gracefully
4. ✅ Ensure all tests pass

Step 1: Write Tests First

describe('buildBalancedTeam', () => {
  const largePokemonPool = [
    { id: 1, name: "Bulbasaur", type: "grass", hp: 45, attack: 49 },
    { id: 4, name: "Charmander", type: "fire", hp: 39, attack: 52 },
    { id: 7, name: "Squirtle", type: "water", hp: 44, attack: 48 },
    { id: 25, name: "Pikachu", type: "electric", hp: 35, attack: 55 },
    { id: 6, name: "Charizard", type: "fire", hp: 78, attack: 84 },
    { id: 9, name: "Blastoise", type: "water", hp: 79, attack: 83 }
  ];

  test('should return team of exactly 3 Pokemon', () => {
    const team = buildBalancedTeam(largePokemonPool);
    expect(team).toHaveLength(3);
  });

  test('should have no duplicate types in team', () => {
    const team = buildBalancedTeam(largePokemonPool);
    const types = team.map(p => p.type);
    const uniqueTypes = [...new Set(types)];
    expect(types.length).toBe(uniqueTypes.length);
  });

  test('should have total attack of at least 150', () => {
    const team = buildBalancedTeam(largePokemonPool);
    const totalAttack = team.reduce((sum, pokemon) => sum + pokemon.attack, 0);
    expect(totalAttack).toBeGreaterThanOrEqual(150);
  });

  test('should prefer higher HP when choosing between same type', () => {
    const team = buildBalancedTeam(largePokemonPool);
    const fireType = team.find(p => p.type === 'fire');
    if (fireType) {
      // Should pick Charizard (78 HP) over Charmander (39 HP)
      expect(fireType.name).toBe('Charizard');
    }
  });

  test('should return empty array when impossible to build team', () => {
    const insufficientPokemon = [
      { id: 1, name: "Bulbasaur", type: "grass", hp: 45, attack: 30 },
      { id: 2, name: "Ivysaur", type: "grass", hp: 60, attack: 35 }
      // Only 2 Pokemon, both same type, low attack
    ];
    
    const team = buildBalancedTeam(insufficientPokemon);
    expect(team).toEqual([]);
  });
});

Step 2: Implement Function Add to utils.js:

export const buildBalancedTeam = (pokemonList) => {
  // Strategy hints:
  // 1. Group Pokemon by type
  // 2. For each type, pick the one with highest HP
  // 3. Sort these "best of type" by attack (highest first)
  // 4. Try to pick 3 different types that meet attack requirement
  // 5. Return empty array if impossible
  
  // Helper: Group by type
  // Helper: Find best Pokemon per type (highest HP)
  // Helper: Check if team meets attack requirement
  
  // Your code here
};

Step 3: Import in Test File

// Step 1: Group by type and pick best of each
const bestByType = {};
// ... group Pokemon by type
// ... for each type, find Pokemon with highest HP

// Step 2: Convert to array and sort by attack
const candidates = Object.values(bestByType)
  .sort((a, b) => b.attack - a.attack);

// Step 3: Try to build team that meets requirements
// ... pick top 3 different types
// ... check total attack >= 150
// ... return team or empty array

Git Workflow

git checkout -b ticket-6-team-builder

git commit -m ":test_tube: test: add buildBalancedTeam structure tests"
git commit -m ":test_tube: test: add team constraints validation tests"
git commit -m ":sparkles: feat: implement Pokemon type grouping logic"
git commit -m ":sparkles: feat: implement team selection algorithm"
git commit -m ":test_tube: test: add edge case for impossible team building"

git push origin ticket-6-team-builder

---